Mary for me. So classic sounding, lots of cool historical namesakes (Stuart, Wollstonecraft, Shelley, Seacole...), pretty diminutive (May), variety of namesake songs etc. It perhaps used to a be bit dull/plain sounding, but underuse these days makes it sound fresher again imo. I'd possibly be slightly nervous of teasing due to associations - Bloody Mary, Virgin Mary, "Hairy Mary"; but if you are brave enough it's a cool name.
In comparison I'm not so keen on the sound of Miriam personally - I think I find the "m" ending a bit harsher/more masculine sounding (William/Liam, Adam, Bertram, Abraham/Bram, Maxim etc) .